Medical catheters are used for the administration of therapeutic agents or nutrients either into a blood stream or a body cavity of a patient. A catheter includes an exit port to deliver solutions, for example nutrients or therapeutic agents, or a combination thereof, from a lumen of the catheter to the body.
Conventional catheters include at least one pressure responsive valve, such as a sleeve valve. A sleeve valve is formed by covering an exit port of the catheter with a sleeve. The sleeve is constructed of an elastic material to provide the sleeve with the ability to expand and contract in response to pressure gradients. The pressure responsive valve opens and, in turn, permits fluid flow through the catheter in response to an applied pressure differential. More particularly, when the pressure differential exceeds a threshold, the fluid in the lumen of the catheter expands the sleeve and flows out of the catheter. When the pressure differential decreases below the threshold pressure differential, the sleeve forms a seal with the exterior of the catheter to prevent fluid flow in or out of the catheter.
Some patients may require an implanted catheter for an extended period of time. However, catheters that remain implanted in a body of a patient may become occluded over time due to blood ingression, thrombus formation or fibrous tissue encapsulation. When a catheter does become occluded, the patient will not receive the necessary therapeutic agents or nutrients. In this case, the catheter must be removed and either cleaned or replaced with a new catheter.